Norbornane and norbornene derivatives, use thereof and perfumed products containing same

ABSTRACT

The invention concerns a novel compounds of formula (I), wherein the dotted line bond is present or not, and wherein R 1  represents: when the dotted line bond is present —CHCH 3 OH or —CHCH 3 OCOR or —CHCH 3 XCH 2 CHOHR′ or —CHCH 3 OCHR′CH 2 OH or formula (II) when the dotted line bond is absent —CHCH 3 OH or —CHCH 3 OCOR or —COCH 3  or formula (II) or —CHCH 3 XCH 2 CHOHR′ or —CH 2 CH 2 XCH 2 CHOHR′ or —CHCH 3 OCHR′CH 2 OH or —CHCHCOR′ or —CH 2 CH 2 CHR′OH or —CH 2 CH 2 CHR′OCOR or CHCHCHOHR′ or —CHCHCHR′OCOR, wherein R represents H, Me, Et, Pr, isoPr, But, isoBut, CH 3 CH 2 ) 4 , (CH 3 ) 2 CHCH 2 , CH 2 CH, (CH3) 2 CCH, and R′ represents H, Me or Et, and X represents O, N or S, and their preparation method. Because of their fragrance, said compounds are highly interesting for the perfume industry, for cosmetic and care products.

FIELD OF THE INVENTION

The present invention relates to novel norbornane or norbornenederivatives, which have a particular fragrance, especially a woody oramber odor, and to their use in the fragrance industry.

The term “fragrance industry” is used herein to denote not onlyperfumery in the strict sense of the word, but also other fields inwhich the odor of products is important, in particular cosmetics,cleaning products, air fresheners and the like.

BACKGROUND OF THE INVENTION

It has been sought for a long time to synthesize novel compounds with agiven odor, for use in the fragrance industry. The inspirational basishas often been natural products, on which attempts have been made toseparate out the molecule(s) with olfactory properties.

In particular, the odor of sandalwood oil has been the subject of muchresearch. After having identified the two main molecules that givenatural sandalwood oil its odor, namely α-santalol and β-santalol,attempts were made to discover other molecules that might contribute tothis odor. Attempts were also made to synthesize molecules that canreproduce this odor. The history of this research is reviewed in thearticle “The Chemistry of Sandalwood Fragrance—a Review of the Last TenYears” by E.-J. Brunke et al., 15th Journées Int. Huiles Essentielles,Dignes-les-Bains, France, 5-7 Sep. 1996.

U.S. Pat. No. 4,229,600 relates to particular norbornane or norbornenederivatives that have the odor of sandalwood oil.

In the search for novel molecules, inspiration was drawn, of course,from the structures of known molecules, but experience has shown thatthe result was often random. Mention may be made, for example, of thearticle mentioned above in which is described a structure/odorcorrelation model, immediately followed by a counterexample, a moleculesynthesized according to this model, but which does not have theexpected odor. This same article cites a certain number of molecules ofsimilar structure but whose olfactory properties are different, somehaving an odor, and others not.

Thus, there is no systematic method for designing a molecule as afunction of the desired odor, from known molecules, via theimplementation of logical and reproducible steps.

SUMMARY OF THE INVENTION

After extensive research, the Applicants have discovered a novel familyof odoriferous molecules.

This family is represented by the following formula:

in which the dotted bond is present or absent, and in which R₁represents:

-   -   when the dotted bond is present        -   —CHCH₃OH or —CHCH₃OCOR or —CHCH₃XCH₂CHOHR′ or            —CHCH₃OCHR′CH₂OH or    -   when the dotted bond is absent        -   —CHCH₃OH or —CHCH₃OCOR or —COCH₃ or        -   or —CHCH₃XCH₂CHOHR′ or —CH₂CH₂XCH₂CHOHR′ or        -   —CHCH₃OCHR′CH₂OH or —CHCHCOR′ or —CH₂CH₂CHR′OH        -   or —CH₂CH₂CHR′OCOR or —CHCHCHOHR′ or        -   —CHCHCHR′OCOR,            in which R represents H, Me, Et, Pr, isoPr, But, isoBut,            CH₃(CH₂)₄, (CH₃)₂CHCH₂, CH₂CH or (CH₃)₂CCH, R′ represents H,            Me or Et, and X represents O, N or S.

DETAILED DESCRIPTION OF THE INVENTION

Each of the compounds of this family may be synthesized directly orindirectly from compound (c) below:

This compound, 1-(2,3-dimethylbicyclo[2,2,1]hept-5-en)-ethanone, whichhas already been described in the literature, and which is referred toin this patent application as Presantone, may be obtained, for example,by condensation of 3-methyl-3-penten-2-one (a) and cyclopentadiene (b),in a Diels-Alder reaction in aqueous phase, catalyzed with methylrheniumtrioxide.

Needless to say, other reactions for preparing Presantone may be used,for example with other catalysts, or a particular solvent.

3-methyl-3-penten-2-one (a) is readily obtained, for example, bycondensation of acetaldehyde or paraldehyde with methyl ethyl ketone.This product is commercially available and inexpensive.

Cyclopentadiene (b) may be obtained, for example, via several knownmethods for the depolymerization of dicyclopentadiene, which is producedby the petroleum industry.

Presantone may be the starting material or an intermediate in thesynthesis of the compounds according to the invention. By way ofnonlimiting example, a reaction scheme for the preparation of novelcompounds according to the invention is given below.

The abbreviations Me, Et, Pr, isoPr, But and isoBut have the usualmeanings known to those skilled in the art, namely methyl, ethyl,propyl, isopropyl, butyl and isobutyl, respectively.

The hydrogenation of Presantone (c) at low temperature (between 20° C.and 50° C.) in the presence of Raney nickel, palladium-on-charcoal orother suitable catalysts gives the saturated ketone (1). This ketone hasa strong resinous woody note, the originality of which is appreciated byfragrance formulators.

According to the invention, the acetal (2) of the ketone (1) with, forexample, propylene glycol, obtained via the standard acetalizationmethods, is hydrogenated in the presence, for example, of purepalladium-on-charcoal or mixed palladium-on-charcoal to open the acetalinto the alcohol ethers (3) and (3′), which are separable bychromatography. The operation is performed with or without a solvent.The process is preferably performed under 30 kg to 120 kg of hydrogen attemperatures of between 120° C. and 180° C. The alcohol ethers (3) and(3′) obtained have a strong, woody, long-lasting odor, whence arisestheir great interest for the fragrance industry, cosmetics, soaps,cleaning products, detergents and other fragranced products. The acetal(2) is itself also a novel compound that is advantageous on account ofits odor.

The reduction of Presantone (c) with sodium borohydride gives theunsaturated alcohol (4), a novel product that is also advantageous.

The standard methods of esterification, for example using the acidanhydrides, allow the esters (5) to be obtained, i.e. the formic,acetic, propionic, butyric, isobutyric, etc. esters especially, from thealcohol (4). These esters are all novel compounds that may be used inthe fragrance industry for their originality in the woody notes.

The hydrogenation of Presantone (c) in the presence of Raney nickel, forexample at temperatures of between 100° C. and 180° C. under 20 kg to100 kg of hydrogen, gives the saturated alcohol (6), which is also anadvantageous compound.

The esterification of this saturated alcohol (6) with acid anhydrides,for example, gives the saturated esters (7), R being a hydrogen, methyl,ethyl, propyl, isopropyl, butyl, isobutyl, CH₃(CH₂)₄, (CH₃)₂CHCH₂, CH₂CHor (CH₃)₂CCH radical. All these novel esters have odors that areadvantageous for the fragrance industry, due to their original fruitywoody nature.

A second route was found from the saturated alcohol (6). Via dehydrationof this alcohol via well-known methods, the ethylenic hydrocarbon (8) isobtained.

Acylation, for example with acetic or propionic anhydride in thepresence of boron trifluoride etherate or zinc chloride, gives theethylenic ketones (9). Any other known acylation method may be used.

Reduction of the ethylenic ketones (9) with sodium borohydride inalcohol is a simple method for obtaining the ethylenic alcohols (12),which are novel compounds that are also very advantageous. The esters(13) of the alcohols (12), obtained via standard methods, for exampleusing the acid anhydrides, develop milder but long-lasting woody noteswhich are also highly appreciated by fragrance formulators.

The total hydrogenation of the ethylenic ketones (9) via the standardmethods gives the saturated alcohols (10), and their esterification viaany usual method, for example using the acid anhydrides, gives theesters (11), R being a hydrogen, methyl, ethyl, propyl, isopropyl,butyl, isobutyl, CH₃(CH₂)₄, (CH₃)₂CHCH₂, CH₂CH or (CH₃)₂CCH radical.These compounds also have advantageous woody odors.

It is also possible to prepare compounds (14) and (14′)—which areseparable by chromatography—by opening ethylene, propylene or butyleneoxide, to give ethylene glycol, propylene glycol or butylene glycol,respectively, with the alkoxide of compound (4):

Another process for preparing compounds (3) and (3′) from compound (6)may be mentioned. These compounds may be obtained from the alkoxide ofcompound (6) via the opening of ethylene, propylene or butylene oxide togive the corresponding glycol:

The invention also relates to another process for preparing compounds(3) and (3′), characterized in that the starting material or anintermediate is the novel compound of formula

in which R′ is H, Me or Et.

The acetal (2′) may also be the starting material or the intermediate inthe synthesis of the compounds of formulae (14) and (14′).

The acetal (2′) may be prepared, for example, directly by Diels-Alderreaction catalyzed with FeCl₃ between cyclopentadiene and the acetal(d).

The acetal (d) (in which R′═CH₃) may be obtained by acetalization fromthe methyl-pentenone (a) and propylene glycol.

In one embodiment, the acetal (2′) allows the synthesis of compounds (3)and (3′), for example via a one-step hydrogenation catalyzed withpalladium-on-charcoal.

The acetal (2′) also allows the synthesis of compounds (14) and (14′)via hydrogenation, for example with a hydride.

The invention also relates to other novel compounds, similar tocompounds (3) and (14), in which the oxygen atom has been replaced witha sulfur or nitrogen atom. These are the compounds (15) to (18) below:

The sulfur compounds (15) [(15a), (15b) and (15c)] may be obtained fromcompound (1) according to the following process:

The oxathiolane (d) may be obtained via a standard acetalization method,and the acetal is then opened regiospecifically via methods described inthe literature, for example with DIBAL in refluxing toluene.

The sulfur compounds (17) [(17a), (17b) and (17c)] may be obtained inthe same manner as above, starting with Presantone (c).

The nitrogen compounds (16) [(16a), (16b) and (16c)] and the sulfurcompounds (15) [(15a), (15b) and (15c)], may be obtained from thealcohol (6), for example via mesylation, tosylation or halogenation,followed by nucleophilic substitution with the corresponding aminoalcohol or thiol:

The amino alcohols (18) [(18a), (18b) and (18c)], and the thioethers(17) [(17a), (17b) and (17c)] may be obtained in the same manner asabove, starting with the alcohol (4). The ethylenic hydrocarbon (8) alsoallows the synthesis of analogs containing a heteroatom in the sidechain:

The primary alcohol or thiol obtained by hydroboration of the doublebond or addition of H₂S is then condensed with ethylene, propylene orbutylene oxide to give compounds (19) [a to c] and (20) [a to c].Propylene oxide may optionally be replaced with the correspondinghaloacetone to give, after reduction with NaBH₄, the expected alcohols(19b) and (20b).

The amino analogs (21) [a to c] may be obtained from the primary alcoholderived from hydrogenation via tosylation (or mesylation), followed by asubstitution with the corresponding amino alcohol:

A subject of the invention is the compounds represented by the generalformula (I) in the form of a mixture of diastereoisomers in variableproportions, in particular the racemic mixtures.

Moreover, some of the diastereoisomers or enantiomers have olfactoryproperties that are as advantageous as the compounds obtained in theform of diastereoisomeric mixtures.

A subject of the invention is also the pure diastereoisomers orenantiomers of the novel compounds represented by the general formula(I), which may be separated by preparative gas chromatography. They mayalso be synthesized from optically active compounds, for example R or Spropylene glycol and the alcohol (6) derived from the enantioselectivereduction of Presantone (1-4), and purified by distillation.

A subject of the invention is also the processes for preparing the novelcompounds.

Each of the novel compounds is advantageous on account of its odor, inparticular its woody odor. Compound (3) with R′=Me is particularlyadvantageous. Moreover, the invention has an obvious economic advantagearising from the simplicity of the reactions used and the low cost ofthe starting materials used.

On account of their olfactory qualities, these various compounds thusfind very varied use in the fragrance industry for the preparation offragrancing bases and concentrates, perfumes and eaux de toilette, andalso in the fragrancing of various consumer articles, such as soaps,shower gels or bath gels, shampoos and other hair hygiene products,cosmetic preparations, body deodorants, air fresheners, or alternativelytextile detergents or softeners and cleaning products.

In these applications, the compounds according to the invention may beused alone or, as is more common in the fragrance industry, as a mixturewith other fragrancing ingredients, solvents or adjuvants commonly usedin the fragrancing industry, and which a person skilled in the art iscapable of selecting as a function of the desired effect and of thenature of the product to be fragranced.

EXAMPLES

The concentrations in which these compounds and the isomeric mixturesthereof may be used to obtain the desired fragrancing effects varywithin a very wide range of values (0.1% to 99%), it being well knownthat these values depend on the nature of the article to be fragranced,the desired odoriferous effect and the nature of the other ingredientsin a given composition.

A subject of the invention is thus also the use of the novel compoundsfor the preparation of a fragrancing composition or a fragrancedarticle, in the applications described above, in particular inperfumery, in cosmetics, for example for shampoos or soaps, and forcleaning products, such as softeners or detergents.

A subject of the invention is also the fragranced products comprising atleast one compound according to the present invention, whether in thefield of perfumery, cosmetics or cleaning.

The examples that follow further illustrate the various processes formanufacturing the novel compounds according to the invention and alsotheir use and their advantage. These examples are given merely for thepurpose of illustration and cannot be considered as limiting theinvention.

Example 1 Diels-Alder Reaction (Presantone (c))

110 g of dry toluene are placed in a 500 ml round-bottomed flask with amagnetic stirrer, a thermometer, an addition funnel, and under nitrogen.

After cooling to 0° C., 4 g of aluminum chloride are added in a singleportion, followed by addition, at about 10° C., of 88 g of 94%3-methyl-3-penten-2-one (a) over 20 to 30 minutes, while cooling gently.

A solution of 66 g of cyclopentadiene (b) in 140 g of dry toluene isthen added, at between 12° C. and 14° C., over 1 hour 10 minutes to 1hour 20 minutes, while maintaining the temperature by cooling.

After separation of the phases by settling, the organic phase is washedwith dilute hydrochloric acid (100 ml) and with a 5% carbonate solution.After concentrating the solvent under vacuum, the product is distilledoff under 2 mm of vacuum (b.p.: 56-70° C./2 mm). 128 g of distillate areobtained. This product is taken up in toluene and treated withtriethylamine and with a sodium carbonate solution. After washing andevaporating off the solvent under vacuum, the product is redistilledunder a vacuum of 1 mm. 112 g of1-(2,3-dimethylbicyclo[2,2,1]hept-5-en)ethanone are obtained (b.p.:56-60° C./1 mm), yield: 76%.

The mixture is left stirring at 14-15° C. for a further 15 minutes andis then cooled to 0° C. and a solution of 20 g of 32% hydrochloric acidin 100 g of water is then added rapidly while allowing the temperatureto rise.

The vapor-phase chromatography analysis shows the presence of two mainisomers (32% and 56%).

The analyses of the infrared and mass spectra correspond to thestructures of the expected compounds.

Example 2 Saturated Ketone (1)

The hydrogenation of 50 g of the ethylene ketone (c) in the presence of0.5 g of Raney nickel at room temperature, and at a low pressure ofhydrogen (1 to 10 kg) absorbs the theoretical amount of hydrogen overabout 2 hours.

After separating out the catalyst, the product is distilled undervacuum. The saturated ketone (1) is obtained virtually quantitatively.

The product distils at 54° C.-58° C. under 1 mm of vacuum. Thevapor-phase chromatography analysis shows two main peaks and theinfrared and mass spectra correspond to the structures of the expectedcompounds.

Example 3 Ethylenic Alcohol (4)

Via reduction of 40 g of Presantone (c) in 200 ml of 96% alcohol, byadding 6 g of sodium borohydride portionwise at 25° C. over 2 hours,followed by gradually bringing the temperature to 40° C. over 2 hoursand maintaining the mixture at this temperature for a further 3 hours,the total reduction of the ketone function to an alcohol is obtained.

After slow acidification, with 2% hydrochloric acid, extraction withtoluene and washing, the product is concentrated under vacuum and thendistilled.

36 g of ethylenic alcohol (4) are obtained, with a boiling point of72-75° C. under 1 mm of vacuum, i.e. 90 mol% yield.

The vapor-phase chromatography analysis shows the presence of 3 mainisomers that have very similar mass and infrared spectra.

Example 4 Ethylenic Esters (5)

By slowly bringing 10 g of ethylenic alcohol (4) in 10 g of aceticanhydride to 115-120° C. over 2 hours, the ethylenic acetate (5) isobtained.

The product obtained is concentrated under a vacuum of 30 mm to distiloff the acid and the excess acetic anhydride through a 25 cm Vigreuxcolumn. The vacuum is slowly increased to 1 mm and the ethylenic acetate(5) is distilled off.

10 g of ethylenic acid (5) are obtained with a boiling point of 73-76°C. under 1 mm of vacuum.

The vapor-phase chromatography, MS and IR analyses correspond with thestructures of the expected compounds.

The propionic, butyric and isobutyric esters of the ethylenic alcohol(4) are obtained by heating the alcohol (4) with the correspondinganhydrides, in the presence of a small amount of toluene, to maintainthe reflux temperature at about 125-130° C.

The reflux time is increased to 2 hours to complete the esterification.

By distillation under vacuum, the acids and the anhydride esters areseparated. By increasing the vacuum, the esters (5) are obtained.

Propionate of the ethylenic alcohol (5) with a boiling point of 80-83°C. under 1 mm of vacuum.

Butyrate of the ethylenic alcohol (5), with a boiling point of 88-91° C.under 1 mm of vacuum.

Isobutyrate of the ethylenic alcohol (5), with a boiling point of 85-88°C. under 1 mm of vacuum.

Example 5 Saturated Alcohol (6)

100 g of ethylenic ketone (c) are placed in an autoclave and are stirredand heated in the presence of 2 g of Raney nickel.

After flushing 3 times with 10 kg of hydrogen, the pressure is broughtto 30 kg and the autoclave is heated to 150-160° C. with stirring.

The hydrogenation is performed under 60 kg of hydrogen until thepressure no longer falls (5 to 6 hours).

The crude saturated product (5) is distilled off under 1 mm of vacuum inan apparatus equipped with a 20 cm Vigreux column.

97 g of alcohol (5) are obtained, with a boiling point of 72-75° C.under 1 mm of vacuum.

The vapor-phase chromatography analysis shows that there are 4 mainisomers, which have very similar mass and infrared spectra.

Example 6 Saturated Esters (7)

The saturated esters are obtained via the standard method used to makethe unsaturated esters (Example 4), i.e. heating the saturated alcohol(6) in the presence of the corresponding acid anhydride.

Among the compounds obtained:

Acetate of the saturated alcohol (7), with a boiling point of 73-76° C.under 1 mm of vacuum,

Propionate of the saturated alcohol (7), with a boiling point of 80-83°C. under 1 mm of vacuum,

Butyrate of the saturated alcohol (7), with a boiling point of 88-91° C.under 1 mm of vacuum,

Isobutyrate of the saturated alcohol (5), with a boiling point of 85-88°C. under 1 mm of vacuum.

Example 7 Alcohol Ether (3)

7.1. Acetal (2)

The acetal of the saturated ketone (1) and of propylene glycol may beprepared by refluxing, using a 30 cm Vigreux column and a waterseparator, propylene glycol (50 g), the ketone (1) (80 g) dissolved intoluene (40 g) and p-toluenesulfonic acid (0.4 g) as acid catalyst. Thewater is removed azeotropically (refluxing for 18 to 20 hours).

The toluene may also be removed and the water eliminated by distillingit off under vacuum.

The reaction mixture is washed with 5% sodium carbonate solution andthen with water to neutral pH.

Fractionation under a strong vacuum in apparatus equipped with a 50 cmVigreux column allows the following to be obtained:

25 g of recovered ketone (1) to be recycled, with a boiling point of54-58° C. under 1 mm of vacuum.

65 g of acetal (2), with a boiling point of 64-58° C. under 1 mm ofvacuum,

10 g of intermediate fractions to be recycled.

7.2. Alcohol Ether (3)

50 g of acetal (2), 100 g of isopropanol and 0.5 g ofpalladium-on-charcoal are placed in a stirred autoclave.

After flushing with hydrogen, the autoclave is maintained at between 160and 170° C. under 50-60 kg of hydrogen for 18 to 24 hours.

The reaction progress is monitored by vapor-phase chromatography and thereaction is stopped when the percentage of acetal (2) has fallen to5-6%.

After separating out the catalyst, the product is distilled off under 1mm of vacuum in an apparatus equipped with a 50 cm Vigreux column. 6 gof head fractions are obtained.

Boiling point 40-50° C., 16 g of ketone (1)+acetal (2), with a boilingpoint of 54-68° C. under 1 mm of vacuum, to be recycled, and 25 g ofalcohol ether (3), with a boiling point of 85-92° C. under 1 mm ofvacuum. The mass and infrared spectra correspond with the structures ofthe expected compounds.

Example 8 Ethylenic Ketone (9)

8.1. Dehydration of the Alcohol (6)

150 g of alcohol (6) and 100 g of boric acid are placed in a 500 mlround-bottomed flask.

The mixture is heated under 40 mm of vacuum to remove the water ofboratization and is then brought to a temperature of 230-250° C. todehydrate. After distilling off 70 to 80 g of ethylenic compound (8),the dehydration is continued by introducing the alcohol (6) gradually asthe dehydration proceeds.

Starting with 1 kg of alcohol (6), 880 g of ethylenic compound (8)containing 7-10% of alcohol (5) are obtained.

By fractionation on a 30 cm Vigreux column, 800 g of ethylenic compound(8) are separated out and 70 g of alcohol (6) to be recycled arerecovered.

8.2. Ethylenic Ketone (9)

120 g of ethylenic compound (8) and 120 g of acetic anhydride are placedin a 1 liter round-bottomed flask with magnetic stirring, and themixture is heated to 70-75° C. 16 ml of boron trifluoride etherate arethen introduced over 15 minutes at 75-80° C. The temperature andstirring are maintained for 3 hours at 80-82° C.

After cooling to about 60° C., the excess acetic anhydride is decomposedby adding, slowly at the start, 320 g of water while maintaining thetemperature at about 60-65° C.

The organic phase is separated out and the aqueous phase is extractedwith twice 60 ml of cyclohexane. The combined organic phases are washedwith 10% sodium carbonate solution and then with water.

After concentrating the solvent under a gentle vacuum, the crude product(138 g) is fractionated in an apparatus with a 30 cm Vigreux column.Under 5 mm of vacuum, 80 g of starting material (8) to be recycled and32 g of ethylenic ketone (9) with a boiling point of 75-88° C. under 1mm of vacuum are recovered.

Example 9 Ethylenic Alcohol (13)

30 g of ethylenic ketone (9) and 75 g of 96° ethanol are placed in a 250ml round-bottomed flask with magnetic stirring and a thermometer. Whilecooling slightly, to maintain 20-25° C., 3 g of sodium borohydride areadded portionwise. After the introduction, the mixture is stirred for 6hours at room temperature and is then gradually heated to 40° C. over 2to 3 hours, and then maintained at 40-45° C. for 4 hours.

A large proportion of the alcohol is concentrated under a gentle vacuum.30 g of water are added to the residue, followed by slow acidification,while maintaining the temperature at 20-25° C., with 16 g ofconcentrated hydrochloric acid diluted with 50 g of water. 30 ml oftoluene are then added, followed by separation of the phases bysettling. The organic phase is separated out and the aqueous phases areextracted with twice 20 ml of toluene. After combining the organicphases, they are washed twice with 80 ml of water. The toluene is thenconcentrated under vacuum and the residue (30 g) is distilled under astrong vacuum in an apparatus equipped with a 15 cm Vigreux column.

25 g of ethylenic acid (12) are thus obtained, with a boiling point of85-92° C. under 1 mm of vacuum, along with 3 g of product to berecycled. The infrared and mass spectra correspond to the structures ofthe expected compounds.

Example 10 Ethylenic Acetate (13)

30 g of ethylenic alcohol (12) and 25 g of acetic anhydride are placedin a 100 ml round-bottomed flask equipped with a magnetic stirrer, athermometer and a 20 cm Vigreux column.

The mixture is heated under a gentle vacuum, such that the bulktemperature is 115-120° C., for 2 hours. The vacuum is then increased todistil off the acetic acid/anhydride mixture. The final bulk temperatureis 125-130° C.

Under 1 mm of vacuum, the acetate (14) with a boiling point of 80-88° C.under 1 mm of vacuum is then distilled off. 27 g of acetate (13) and 3 gof product to be recycled are obtained. The infrared and mass spectracorrespond to the structures of the expected compounds.

Example 11 Saturated Alcohol (10)

30 g of ethylenic ketone (9) and 0.6 g of Raney nickel are placed in astirred and heated autoclave. After flushing with hydrogen, the mixtureis brought to 150-160° C. under 60 kg of hydrogen.

The reaction is complete after 12 hours. The catalyst is separated outand the product is distilled off under a strong vacuum. 27 g ofsaturated alcohol (11) are obtained, with a boiling point of 82-90° C.under 1 mm of vacuum.

Example 12 Saturated Acetate (12)

By performing the process as for the ethylenic acetate (13) on 25 g ofsaturated alcohol (10), 26 g of acetate (11), with a boiling point of78-86° C. under 1 mm of vacuum, are obtained by distillation.

Example 13 Alcohol Ether (3) via the Acetal (2′)

46.00 g of dichloromethane are placed under nitrogen in the receivingflask of a distillation apparatus on which is mounted a 30 cm Vigreuxcolumn, and the flask is cooled to 0° C. The oil bath of thedistillation apparatus is heated to about 195° C. in order to obtain atemperature of 165° C. inside the three-necked flask. 13.80 g (0.45 mol)of dicyclopentadiene are introduced dropwise via the top of the column,the cyclopentadiene thus freshly depolymerized being recovered in thecooled solvent. 56.00 g of a solution of cyclopentadiene indichloromethane, i.e. a potential of 10.00 g of cyclopentadiene (0.151mol) are obtained over 4 hours. Yield: 72.5%. The solution is useddirectly in the following Diels-Alder reaction.

14.80 g (0.076 mol) of 80.0%2,4-dimethyl-2-(1-methyl-propenyl)[1,3]dioxalane and 1.5 g of iron (III)chloride silica are introduced into the round-bottomed flask undernitrogen and at room temperature, and the mixture is cooled to 0° C.56.00 g of the solution of cyclopentadiene in dichloromethane are addeddropwise at this temperature over 10 minutes. The mixture is stirred for2 hours at 0° C. and then for 15 hours while allowing the bulktemperature to return to room temperature. The catalyst is filtered offand the solvent is evaporated under reduced pressure (about 35mmHg=4.67×10³ Pa). 23.00 g of a pale yellow oil are obtained, and aretransferred into a microdistillation apparatus with a 15 cm Vigreuxcolumn. 1.5 g (5.6 mmol) of 83%2-(2,3-dimethylbicyclo[2.2.1]hept-5-en-2-yl)-2,4-dimethyl-[1,3]dioxalane(sum of the isomers) are obtained. Yield: 7.4%.

Example 14 Olfactory Evaluation

In a first stage, the olfactory characteristics of compound (3) when R′is methyl were evaluated by a panel at the same time as the olfactorycharacteristics of commercially available known compounds. Theevaluation panel is composed of several professionals, who evaluate eachcompound qualitatively and quantitatively. The results of theevaluations are collated in the table below.

Odor: Vet- Woody Cedar Amber iver Iris Camphor Leather Com- XXX XX XX XXpound (3) Iso E XXX X XXX X Super⁽¹⁾ Vertofix⁽²⁾ XXX XX XX X Bois- XXXXX X ambrene⁽³⁾⁽¹⁾2-Acetyl-1,2,3,4,5,6,7,8-octahydro-2,3,8,8-tetra-methylnaphthalene(mixture of isomers); from: International Flavors & Fragrances, USA.⁽²⁾4-Acetyl-1,1,6-trimethyl-6,8a-ethano-1,2,3,4,5,6,7,8,8a-octahydronaphthalene;from: International Flavors and Fragrances, USA.⁽³⁾(Ethoxymethyl)cyclododecane; from: Henkel.

These three reference products are very widely used in fragrancingcompositions for soaps, detergents and softeners or shampoos. They arealso very commonly used in alcohol-based perfumery.

It may be observed that compound (3) has a woody, cedar, amber andcamphor nature.

In a second stage, the impact or the olfactory characteristics ofcompound (3) when it is applied to a support were evaluated.

Three different supports were used:

-   -   as a 10% solution in 96° alcohol,    -   in a standard softening base at 0.5%: evaluation on wet laundry        and on dry laundry,    -   in a standard shampoo base at 0.5%: evaluation of the base        coverage and diffusion in solution in hot water.

Two base fragrancing compositions were prepared by mixing theingredients listed below. The tests were performed by adding 50 parts byweight of compound (3) to the base mixture.

COMPOSITION 1 Test in detergent (application at 0.5%) COMPONENTS TEST 1TEST 2 GERANIUM RECO VMF⁽¹⁾ 20 20 BENZYL ACETATE 60 60DIMETHYLBENZYLCARBINYL ACETATE 20 20 PHENOXYALLYL ACETATE 2 2PHENYLETHYL ALCOHOL 100 100 HEXYLCINNAMALDEHYDE 200 200 C12LAURYLALDEHYDE 2 2 C12 MNA ALDEHYDE 3 3 GAMMA-UNDECALACTONE 7 7CITRONELLOL 30 30 COUMARIN 15 15 DIHYDROFLORIFONNE⁽²⁾ 1 1DIHYDROMYRCENOL 50 50 VERDYL ACETATE⁽³⁾ 15 15 MADAGASCAR CLOVE ESS. 1212 LILIAL⁽⁴⁾ 70 70 METHYLIONONE 55 55 PHENYL OXIDE 25 25 ROSE OXIDE 3 3AMYL SALICYLATE 95 95 BENZYL SALICYLATE 135 135 TRIPLAL⁽⁵⁾ 4 4 VERDOX⁽⁶⁾20 20 OXYPHENYLON at 10% EDG 6 6 COMPOUND (3) 50 TOTAL 950 1000 ⁽¹⁾V.MANE FILS ⁽²⁾1-(2,6,6-trimethyl-3-cyclohexen-1-yl)-2-buten-1-one⁽³⁾3a,4,5,6,7,7a-hexahydro-4,7-methano-1H-inden-5 (or 6)-ol acetate -from Givaudan (Switzerland)⁽⁴⁾p-tert-butyl-alpha-methyl-hydrocinnamaldehyde - from Givaudan(Switzerland) ⁽⁵⁾2,4-dimethyl-3-cyclohexene-1-carbaldehyde - from IFF(International Flavors and Fragrances, United States)⁽⁶⁾2-tert-butylcyclohexyl acetate - from IFF

COMPOSITION 2 Test in fragrance (application at 7%) COMPONENTS TEST 1TEST 2 STYRAX RECO VMF⁽¹⁾ 5 5 ISOBORNYLCYCLOHEXANOL to 50% EDG 90 90YLANG RECO⁽¹⁾ 25 25 BENZYL ACETATE 80 80 PHENYLETHYL ALCOHOL 80 80ANISALDEHYDE 10 10 BACDANOL⁽²⁾ 20 20 CITRONELLOL 55 55 COUMARIN 35 35DIHYDROMYRCENOL 20 20 ETHYLVANILLIN 7 7 GALAXOLIDE⁽³⁾ 140 140 GERANIOL80 80 HELIOTROPINE 10 10 PURE IRISONE⁽⁴⁾ 25 25 LILIAL 45 45 METHYLIONONE25 25 BENZYL SALICYLATE 80 80 VANILLIN 8 8 VERTENEX⁽⁵⁾ 80 80 C10CAPRYLALDEHYDE at 10% DPG 10 10 C12 LAURYLALDEHYDE at 10% DPG 15 15INDOL at 10% DPG 5 5 COMPOUND (3) 50 TOTAL 950 1000 ⁽¹⁾V. MANE FILS⁽²⁾4-(2,2,3-trimethyl-3-cyclopentenyl)-2-ethyl-3-buten-1-ol - from IFF⁽³⁾1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-(g)-2-benzan -from IFF ⁽⁴⁾mixture of ionones ⁽⁵⁾4-tert-butylcyclohexyl acetate - fromIFF

In each case, the evaluations of the olfactory impact were performed att₀, t_(+48h) and t_(+168h) to evaluate the head note, core note andbackground note.

In all cases, it is observed that compound (3) gives an advantageoushead note and base coverage, with a rich and original woody, camphornature.

Whether in alcoholic solution (composition 2) or in a softeningcomposition (composition 1), the rich woody amber note is veryperceptible after 48 hours of drying and gives an original touch that isboth clean and cosmetic.

The loss of intensity over time appears to be fairly linear without anyappreciable change in olfactory characteristic being noticeable.

The diffusion in hot water in shampoo produces a discreet butsophisticated and very pleasant woody nature.

The results of these evaluations show unequivocally that compound (3)has advantageous olfactory characteristics, which will find applicationin particular in cosmetics, perfumery and cleaning products.

1. A novel compound of formula:

in which the dotted bond is present or absent, and in which R₁represents: when the dotted bond is present —CHCH₃OH or —CHCH₃OCOR or—CHCH₃XCH₂CHOHR′ or —CHCH₃OCHR′CH₂OH or

when the dotted bond is absent

or —CHCH₃OH or —CHCH₃OCOR or —COCH₃ or —CHCH₃XCH₂CHOHR′ or—CH₂CH₂XCH₂CHOHR′ or —CHCH₃OCHR′CH₂OH or —CH═CHCOR′ or —CH₂CH₂CHR′OH or—CH₂CH₂CHR′OCOR or —CH═CHCHOHR′ or —CH═CHCHR′OCOR, in which R representsH, Me, Et, Pr, isoPr, But, isoBut, CH₃(CH₂)₄, (CH₃)₂CHCH₂, CH₂═CH or(CH₃)₂C═CH, R′ represents H, Me or Et, and X represents O, N or S. 2.The compound as claimed in claim 1, wherein the dotted bond is absentand R₁ is selected from the group consisting of —CHCH₃OCH₂CHOHCH₃ and—CHCH₃OCHR′CH₂OH.
 3. The compound as claimed in claim 1, in the form ofeither a diastereoisomer or an enantiomer.
 4. The compound as claimed inclaim 1, in the form of a mixture of diastereoisomers.
 5. The compoundas claimed in claim 1, in the form of a racemic mixture.
 6. Afragrancing ingredient for the preparation of either a fragrancingcomposition or fragranced article, said ingredient consisting of acompound of claim
 1. 7. A product selected from the group consisting offragranced products, perfumes, eau de toilette, cosmetic products,soaps, shower gels, bath gels, shampoos, hair hygiene products, cleaningproducts, detergent products, softening products, body deodorizers, andair fresheners, wherein said product comprises a compound as claimed inclaim
 1. 8. A process for preparing a compound as claimed in claim 1comprising: (a) hydrogenating or reducing an unsaturated ketone offormula

(b) reacting the compound resulting from (a) with a compound of formulaR′CHOHCH₂OH or R′CHOHCH₂NH₂ or R′CHOHCH₂SH or RCOOCOR

wherein R′ represents H, Me or Et, and R represents H, Me, Et, Pr,isoPr, But, isoBut, CH₃(CH₂)₄, (CH₃)₂CHCH₂, CH₂═CH or (CH₃)₂C═CH, or(b′) dehydrating compound resulting from (a), reacting with R′COOCOR′wherein R′ is as defined above, (c) optionally hydrogenating or reducingthe compound resulting from (b) or (b′) (d) optionally reacting thecompound resulting from (b′) and (c) with RCOOCOR wherein R is asdefined above.
 9. A process according to claim 8 for preparing acompound as claimed in claim 1 comprising: (a) hydrogenating anunsaturated ketone of formula

(b) reacting the compound resulting from (a) with a compound of formulaR′CHOHCH₂OH wherein R′ represents H, Me or Et, and (c) hydrogenating theresulting acetal of formula

wherein R′ represents H, Me or Et, to open said acetal.
 10. A processaccording to claim 8 for preparing a compound as claimed in claim 1wherein an unsaturated ketone of formula

is prepared by reacting 3-methyl-3-penten-2-one with cyclopentadiene.11. A process for preparing a compound as claimed in claim 1 in which R1is selected from the group consisting of —CHCH₃OCH₂CHOHR′ and—CHCH₃OCHR′CH₂OH wherein R′ is H, Me or Et comprising hydrogenating orreducing an acetal of formula

wherein R′ represents H, Me or Et.
 12. A process according to claim 11for preparing a compound as claimed in claim 1 wherein an acetal offormula

wherein R′ represents H, Me or Et, is prepared by reactingcyclopentadiene with an acetal of formula

(d) wherein R′ is as defined above.